1. Related Applications
This application is related to U.S. Ser. No. 08/192,522, now pending, entitled METHOD/SYSTEM TO DETERMINE GROSS COMBINATION WEIGHT OF VEHICLES, filed Feb. 7, 1994, and assigned to the same assignee, EATON CORPORATION, as is this application.
This application is related to U.S. Ser. No. 08/225,271, now pending, entitled ENGINE DECELERATION DETERMINATION METHOD/SYSTEM, filed Apr. 8, 1994, and assigned to the same assignee, EATON CORPORATION, as is this application.
This application is related to U.S. Ser. No. 08/242,825, now pending, entitled ENGINE FLYWHEEL TORQUE DETERMINATION METHOD/SYSTEM, filed May 16, 1994, and assigned to the same assignee, EATON CORPORATION, as is this application
This application is related to U.S. Ser. No. 08/242,824, now pending, entitled ENGINE ACCESSORY TORQUE AND ENGINE DECELERATION RATE DETERMINATION METHOD/SYSTEM, filed May 16, 1994, and assigned to the same assignee, EATON CORPORATION, as is this application.
This application is related to U.S. Ser. No. 08/285,467, now pending, entitled METHOD/SYSTEM FOR DETERMINATION OF GROSS COMBINED WEIGHT OF VEHICLES EQUIPPED WITH ELECTRONIC DATA LINKS, filed Aug. 3, 1994, and assigned to the same assignee, EATON CORPORATION, as is this application.
2. Field of Invention
This invention relates to systems/methods for determining a value indicative of vehicular gross combined weight (GCW) in vehicles equipped with automated transmission systems or manual transmission systems and electronic data links. In particular, the present invention relates to a system/method for determining the GCW of vehicles, such as heavy-duty trucks or coaches equipped with an electronic databus carrying engine torque and other information, such as a databus conforming to the CAN, SAE J1922 and/or SAE J1939 protocol, wherein the control parameter indicative of GCW is a filtered, averaged value, often an average of 500 or more individual determination iterations, to minimize the effects of driveline torsionals, noise and the like. More particularly, the present invention relates to a GCW value determination method/system wherein the GCW control parameter is a filtered, averaged value and wherein the GCW control parameter value is reset to a default value thereof upon the occurrence of certain conditions, such as the condition of sensing that the vehicle is at rest for greater than a predetermined period of time, which are deemed indicative of vehicle stoppage to change load.
3. Description of the Prior Art
In a heavy-duty truck or tractor-semitrailer vehicle, vehicle GCW may vary in a range of from about 10,000 pounds up to about 80,000 pounds or more, depending upon vehicle type and load. It is highly desirable to inform the vehicle operator of at least approximate current GCW and/or to provide this information to vehicle systems such as, e.g., an automated transmission system, a fleet management system, a variable suspension system, an onboard central tire inflation system (CTIS), an antilock brake system (ABS) or the like.
It is known in the prior art to provide various scale systems for vehicles wherein a control parameter indicative of vehicle weight, or at least of the weight of the vehicle load, may be measured. See, e.g., U.S. Pat. Nos. 4,714,122; 4,728,922; 5,014,206 and 4,839,835, the disclosures of which are incorporated herein by reference.
These systems required scale or other weighing systems which were costIV to provide and/or maintain and were best suited for vehicles, such as garbage trucks or dump trucks, involved in special haulage applications, such as commercial refuse disposal or the like.
In aforementioned co-pending application U.S. Ser. No. 08/192,522, entitled METHOD/SYSTEM TO DETERMINE GROSS COMBINATION WEIGHT OF VEHICLES, a method/system for calculating GCW as a function of engine/drivewheel torque and vehicle acceleration, as read from signals on a data link and/or outputted by various sensors, is disclosed. According to that method/system, the GCW of a vehicle may be determined from known drive train characteristics (transmission ratio, axle ratio, tire radius, etc.), engine torque and vehicle acceleration measured at time t.sub.1 and t.sub.2 if t.sub.1 and t.sub.2 are relatively close (within seconds). This may be expressed as: EQU GCW=(T.sub.1 -T.sub.2).div.((A.sub.1 -A.sub.2).times.C)
where:
Ti=Wheel torque at time t.sub.1 ; PA1 Ai=Vehicle acceleration at time t.sub.1 ; and PA1 C=Wheel rolling radius.div.gravity constant.
To minimize the effects of drivetrain torsionals, noise and the like, GCW is, preferably, determined during or immediately after completion of an upshift and the control parameter GCW.sub.CP is a running, filtered average of many individual iterations of GCW determination. While the above-described method/system is very effective, it is not totally satisfactory as, in certain circumstances, it might not be as responsive as desired to situations wherein vehicles have stopped to change their loading, such as, for example, by adding or unloading cargo, connecting or disconnecting a semitrailer taking on or discharging coach passengers, or the like.